Direct recycling of lithium-ion battery scraps for manufacturing a new anode

Abstract

An improved method of recycling lithium-ion battery anode scraps is provided. The method involves isolating an anode scrap including a graphite anode film adhered to a current collector foil with a polyvinylidene fluoride binder. The anode scrap is combined with deionized water to form a first mixture. The graphite anode film is delaminated from the current collector foil to form a second mixture comprising a free collector foil and a free graphite anode film. The free graphite anode film is filtered and dried from the second mixture to recover the free graphite anode film. The free graphite anode film is combined with a solvent comprising N-methyl-2-pyrrolidone (NMP) to form an anode formation slurry. The slurry is coated onto a copper current collector to produce a new anode.

The invention claimed is: 
     
       1. A method of recycling lithium-ion battery anodes, said method comprising:
 isolating an anode scrap, the anode scrap comprising a graphite anode film adhered to a current collector foil with a polyvinylidene fluoride (PVDF) binder; 
 combining deionized water with the anode scrap to form a first mixture; 
 delaminating the graphite anode film from the current collector foil to form a second mixture comprising a free collector foil and a free graphite anode film; 
 filtering and drying the free graphite anode film from the second mixture to recover the free graphite anode film; 
 combining the free graphite anode film with a solvent comprising N-methyl-2-pyrrolidone (NMP) to form an anode formation slurry; and 
 wherein combining the deionized water with the anode scrap occurs before delaminating the graphite anode film from the current collector foil. 
 
     
     
       2. The method of  claim 1  wherein the current collector foil comprises copper. 
     
     
       3. The method of  claim 1  further comprising the step of using the anode formation slurry in the manufacture of a new anode. 
     
     
       4. The method of  claim 1  further comprising the step of shredding the anode scrap into a collection of smaller anode fragments before the step of combining deionized water with the anode fragment to form a first mixture. 
     
     
       5. The method of  claim 1  further comprising the step of modulating a temperature of the first mixture. 
     
     
       6. The method of  claim 1  further comprising milling the free graphite anode film and free collector foil. 
     
     
       7. The method of  claim 1  further comprising sieving the free graphite anode film and free collector foil. 
     
     
       8. The method of  claim 1  wherein the first mixture consists of deionized water and the anode scrap. 
     
     
       9. The method of  claim 1  wherein the method is performed at a temperature of from 15 to 100 degrees Celsius. 
     
     
       10. The method of  claim 1  wherein the method is performed at room temperature. 
     
     
       11. The step of delaminating the graphite anode film from the current collector foil of  claim 1 , wherein the step occurs in under 30 minutes. 
     
     
       12. The step of delaminating the graphite anode film from the current collector foil of  claim 1 , wherein the step occurs in under 10 minutes.